Jawabanmu

2014-08-27T20:58:13+07:00
V(akhir) = v(awal) + a x t
v(akhir) = 2400 m/s + 20 m/s² x 90 s
v(akhir) = 2400 m/s + 1800 m/s
v(akhir) = 4200 m/s
2 4 2